Various telephone arrangements have been implemented to assist hearing-impaired persons when they are using a telephone. For example, a well known device has been a magnetic pickup coil connected to a hearing aid, which could be attached to a certain marked location on the handset and provide the hearing impaired person with a satisfactory hearing level.
Another aid has been a telephone handset with a receiver amplifier and a volume control in the form of a potentiometer. It is well known to provide a telephone amplifier in the handset of a conventional telephone to vary the amplitude of audio signals received from the telephone subset using a potentiometer. Generally, an amplifying receiver and a volume control in the form of a potentiometer are located in the handset and a user varies the receiver volume to suit the user's need by rotating the potentiometer. A handset amplifier of the above-described general type is disclosed in U.S. Pat. Nos. 4,151,376 and 3,254,160. Another telephone handset amplifier disclosed in U.S. Pat. No. 4,466,120 utilizes a rocker switch located in the handset to control the amplifier to vary the receiver volume. U.S. Pat. No. 4,773,088 describes a telephone handset amplifier circuit for receiving and amplifying an audio signal from a telephone subset by varying amounts based on the duration of operation of a switch and for converting the amplified audio signal into audible sound. The amount of amplification is determined by a variable impedance element such as a FET. An RC circuit controls the impedance of the FET based on the state of the switch and the level of a supply voltage generated in the transmitter portion of the circuit. An electret condenser microphone regulates or stabilizes the supply voltage and provides improved linearity and low transmitter distortion.
U.S. Pat. Nos. 5,867,573 and 6,304,654 describe a telephone handset interface that reduces or eliminates feedback-induced singing in a telephone handset/hybrid loop. The interface provides for user selectable volume control settings, each setting representing an amount of gain or loss to be applied to the transmit and receive signals within the telephone set. The gain settings are selected to limit overall loop gain so as to reduce or eliminate any tendency of the handset to sing at high receive gain levels. Loss inserted into the transmit circuit is removed when user speech is detected in the transmit circuit. The handset interface is preferably constructed as an electronic circuit controlled by a microprocessor. The handset interface contains a volume control circuit which allows the telephone user to vary up or down the amount of gain applied to the receive and transmit signals passing between the handset and the hybrid, thus affecting the amplitude of the signals which ultimately pass through tip and ring between the telephone user and a caller on the far end of the call. Although this handset provides improvements in volume and noise control during a telephone call, this device only works with one party to a telephone.
Current telephones allow a user to alter the unit's volume control to adjust for different acoustics, hearing levels, and physical environments. However, the current technology is not user-friendly in cases where at least one of the parties in a telephone conversation is hearing impaired or speech impaired, since it may be difficult for one party to hear the complete message of the other. For example, when a hearing impaired person is attempting to listen on the telephone, often the conversation is interrupted by requesting louder repetition of the last statement, while at the same time increasing the volume on the recipient's handset.
What is needed is a method, apparatus and system to enable a first party of a telephone conversation to increase the volume control of the first party's handset, while simultaneously increasing the microphone gain of the second party's handset. Thus, optimal gain and noise cancellation takes place at the source, instead of only increasing the volume on the receiving side, which would also increase any transmitted background noise. With a new product of this nature, a hearing impaired or speech impaired person can conduct a telephone conversation in a more natural way, without having to request the other party to speak louder (or softer) as required, or increasing the volume that also includes background noise from the other party.